Cobalt-base superalloys disclosed and claimed in U.S. Pat. No. 3,383,205 have superior oxidation and hot corrosion resistance and as a consequence have long been used extensively in commercial production of industrial gas turbine nozzles. In fact, one of those superalloys is the current first stage nozzle alloy of General Electric Company, the assignee hereof The creep rupture and fatigue strength of that alloy, however, are marginal for new industrial gas turbine nozzle applications and in recognition of that fact, a program was launched to improve those properties without significantly diminishing the resistance of the superalloy either to oxidation or to hot corrosion. While the resulting superalloys met those objectives as a consequence of their relatively high carbon contents (0.40 to 0.50%), they were still not the answer to the problem because of their inferior weldability and low tensile ductility.